It was the end of a long, hot day in Israel when it happened: Republican lawmakers, along with a smattering of aides and family members, dived into the Sea of Galilee, a holy site for Christians where the Bible says Jesus walked on water.

Several GOP sources familiar with the events on August 4, 2011 said one of those Republicans, Rep. Kevin Yoder of Kansas, wasn't wearing any clothes. Others say they dived in for religious reasons.

The incident happened a year ago, but the repercussions are just now being felt in Washington after a report in Politico detailed the trip and an ensuing FBI investigation. A law enforcement official said the FBI looked at the incident in Israel, saying the late-night swimming was probed to determine if U.S. officials were putting themselves at risk, or if any information the lawmakers possessed could have been exposed by a night of drinking and partying. This official did not believe there was any damage.

A source said the group was prodded to jump into the water by waiters at the restaurant where they were eating, who told the crowd of lawmakers, aides and family members that patrons regularly jumped into the water on hot days. The waiters themselves jumped into the water first as a demonstration to the Americans.

"There's no question there was a sense of lightheartedness and there were those who were drinking alcohol," said Rep. David Schweikert of Arizona, who was at the dinner but did not swim.

After prodding from the waiters, some of the Americans dived in. Of the 30 members of Congress on the trip, a little more than half went swimming in the Sea of Galilee.

Yoder, who's serving his first term in Congress, was among the last to jump in, and was the only one who was completely nude. As he dived into the water naked, someone screamed that he was not wearing any clothes, according to the GOP sources.

Soon after that the swim came to an end.

As the trip began last August, several of the Republican members participating told GOP Whip Kevin McCarthy that they wanted to swim in the Sea of Galilee for religious reasons, and at least two congressmen on the trip say they swam, fully clothed, because of the spiritual significance of the body of water.

Rep. Steve Southerland of Florida jumped in holding his 21-year-old daughter's hand. She is now headed to be a missionary.

Rep. Tom Reed of New York swam with his wife Jean. Reed's spokesman Tim Kolpien said the pair "swam together with a large group – appropriately clothed. There was no impropriety and he is unaware of any investigation."

Sources said when McCarthy and Republican Majority Leader Eric Cantor found out about the group swim, the two GOP leaders were furious. They called a members-only meeting the next morning to reprimand the group – both those who swam and those who abstained.

"Twelve months ago, [Cantor] dealt with this immediately and effectively to ensure such activities would not take place in the future," Cantor spokesman Doug Heye wrote in a statement Sunday after reports of the incident emerged.

Kevin Smith, a spokesman for House Speaker John Boehner, wrote that" [Cantor] handled the situation swiftly and appropriately."

Rep. David Schweikert of Arizona, who was on the Israel trip but did not go swimming, described a "high level of annoyance" from Cantor and McCarthy, and characterized the meeting as a "scolding."

McCarthy and Cantor were afraid that news of the swim would leak, anticipating how bad it would look for members of Congress to be seen drinking and swimming late at night. They were mostly worried, however, because Yoder took off his clothes and jumped into the water in front of the whole group – including at least two female staffers.

Senior House Republicans were also concerned about the timing of the incident, which came right after a bitter fight over raising the federal debt limit and as the stock market was tumbling.

Rep. Schweikert framed the late night swim as an example of a lack of judgment, pointing particularly to Rep. Ben Quayle, who he will face in a GOP primary to represent Arizona's 8th Congressional district in a little more than a week.

Anna Haberlein, a spokeswoman for Ben Quayle's campaign, said their rivals were "opportunistically promoting the story," writing "They lie for convenience. They aren't real leaders and they will do and say anything to stay in office."

Quayle, himself, also weighed in with a statement: "The real question here is why is Dave Schweikert spreading these malicious falsehoods, a week before our primary, if he has known about inappropriate behavior for over a year? The mask is off and Dave Schweikert has revealed himself as exactly the low and dishonest career politician the public has come to loathe."

Quayle's wife – who was more than eight months pregnant during the trip to Israel - wrote in a statement to CNN that neither she nor her husband had any knowledge of the skinny dipping incident.

"Ben and I and our daughter Evie were there together that evening in the Holy Land, although I was eight and a half months pregnant with her," Tiffany Quayle wrote. "We were neither party nor witness to any of the inappropriate behavior described in the article, nor were we a part of, or aware of any inquiry. We did return to Arizona with some water from the Sea of Galilee to baptize Evie after she was born."

Quayle's office said Monday that the Arizona Republican "proudly [swam] for religious reasons," but was not a part of the larger group.

Another Republican on the trip, Rep. Renee Ellmers, left the restaurant before the swimming incident and learned about it the next day, according to a senior GOP aide.

A spokesman for the Democratic Congressional Campaign Committee, which is charged with electing Democrats to the lower chamber, wrote in a statement Monday the Israel antics looked "more like a scene out of Animal House than a delegation of Members of Congress representing America in Israel – one of our most important security partners."

"Republican leaders knew that these House Republicans' behavior was inappropriate and wrong, but kept the FBI investigation under wraps for more than a year," DCCC communications director Jesse Ferguson wrote. "What other inappropriate, embarrassing behavior have Republican Members of Congress been engaged in that Republican Leaders are keeping under wraps? It's getting harder and harder to keep track of this House of Scandal given how many House Republicans face FBI investigations."

A GOP aide, however, maintained that the story would mostly play in Washington, rather than in the Republican lawmakers' districts. Yoder is running unopposed by a Democrat in his race for re-election.

The congressman apologized in a statement, writing "regrettably I jumped into the water without a swimsuit."

"It is my greatest honor to represent the people of Kansas in Congress and [for] any embarrassment I have caused for my colleagues and constituents, I apologize," Yoder added.